German Patent Disclosure DE 43 36 860 A1 discloses a two-connection/two-position valve of the generic type involved here, known for short as a 2/2-way valve; it has a housing that has a longitudinal bore, a valve seat resting in the housing, a closing body associated having the valve seat, a tappet connected to the closing body and displaceable in the longitudinal bore, an opening spring engaging the tappet, an armature, oriented toward the tappet, for displacing the closing body enclosing the valve seat, and an electromagnet which has a magnetic coil. This 2/2-way valve is intended for installation in a hydraulic vehicle brake system and in particular in an anti-skid brake system for conditionally dependent variation of wheel brake pressures in wheel brake cylinders to avoid the danger of wheel locking. However, such a 2/2-way valve can also be used for arbitrary electrically controllable variation of brake pressure and for automatic variation of brake pressure, for instance to limit drive slip at drivable wheels by braking, or to generate wheel brake slip for the sake of side slip generation to change the driving performance of a vehicle equipped with it. As the name, two-position valve, indicates, the only positions this valve assumes are "open" and "closed". Because of the relatively small structural size of the 2/2-way valve and hence of its electromagnet, its armature directs the closing body to the valve seat lightning-fast, and conversely because of the short return time of the armature to its outset position, this 2/2-way valve is also opened very fast, resulting in the generation of irritating noise in the vehicle brake system. To counteract such irritating noise production, the 2/2-way valve of DE 43 36 860 A1 is assigned a damping device, which for instance as shown in FIG. 1 comprises a cylinder, a piston displaceable in the cylinder, and a damping spring acting on the piston. The cylinder has one connection on each of its ends; the first connection communicates with a first connection of the 2/2-way valve, and the second connection communicates with a second connection of the 2/2-way valve. If there is a flow through the normally-open 2/2-way valve so that the valve is closed lightning-fast, then the damper, by displacement of its piston counter to the force of its damper spring, absorbs kinetic energy from the flowing medium, thereby both limiting the rates of pressure change and limiting pressures, and thus lessening the sources of noise production. The high technological expense for the damper is a disadvantage.
Another 2/2-way valve, in accordance with German Patent Disclosure DE 40 35 817 A1, is provided with a hydraulic damper which has a piston and a check valve and which, on the opening of the 2/2-way valve by means of an opening spring, on the occasion of the displacement of the tappet together with the closing body, presents a speed-dependent resistance, and as a result limits the speed of displacement of the tappet and thus of the closing body. Such a damper, using a piston, is expensive, especially because it is necessary to manufacture a damper cylinder or damper cylinder bore with the smoothest possible surface. If the damper piston is equipped with a sealing sleeve, then a throttle in the wall of the damper cylinder is also needed, but its cross section is narrow and it can therefore tend to become soiled, thus causing perhaps excessively slow opening of this 2/2-way valve. That would lead to an overly low flow of pressure fluid per unit of time and hence to a slow buildup of brake pressure and a long vehicle braking distance. One advantage is that by the intentionally slowed opening of the 2/2-way valve, volumetric flows arise in delayed fashion, and as a result pressure changes caused by these volumetric flows are likewise delayed, which aids in avoiding disadvantageous noise development.